1. Field of the Invention
The present invention relates to an apparatus for winding a cord, and more particularly, to an apparatus for winding a cord, in which a winding operation and a wind stopping operation are performed by pulling the cord of an ear-microphone of a portable cordless telephone, etc.
2. Description of the Related Art
Hands-free ear microphones are increasingly used due to the spread of portable cordless telephone usage. The hands-free ear microphone includes a cord, a plug connected to one end of the cord, and an earphone and a microphone connected to other end of the cord. When using the hands-free ear microphone, the plug is inserted into an earphone jack of the portable cordless telephone. The earphone is generally worn by insertion in an ear channel. If the portable cordless telephone is used while being carried on user""s belt or in a pocket, the cord is extended long enough from the ear to the belt or the pocket. The extended cord length requires caution to avoid entanglement with the user, may be uncomfortable and may affect the user""s behavior. Further, if the cord is caught by a protrusion, etc., the user may be inconvenienced or burdened by the cord""s presence.
If the portable cordless telephone is not used, the ear microphone is bunched up and stowed, e.g., in a pocket, etc. Then, when taking out the ear microphone from the pocket to use it again, since the cord is twisted or entangled, the user needs to untangle the cord, thereby causing inconvenience or even damage to the device.
Therefore, an apparatus for arranging and storing the cord is needed. Typically, cord winding apparatuses in which the cord is wound on a bobbin or a reel using restoring force of a spiral spring have been disclosed, where the cord is drawn out when in use.
In Korean laid-open publication No.200-63791, there is disclosed xe2x80x9ca side open type bi-directional earphone cord winding apparatusxe2x80x9d.
The conventional apparatus includes a side-opened winding case and a bobbin. A guide groove is formed in an inner side surface of the winding case and an outer side surface of a bottom portion of the bobbin, which is contacted with the inner side surface of the winding case. A ball is inserted into a space formed by the guide grooves so as to stop rotation of the bobbin, which would be caused by the spring, or to release the stopping operation while being moved along the guide groove in combination with an operation of drawing the cord out of the bobbin or winding the cord on the bobbin using the spring.
In the conventional apparatus, the spiral guide groove is formed in the outer side surface of the bottom portion of the bobbin. And, the guide groove corresponding to the spiral guide groove is formed in the inner side surface of the winding case, which is contacted with the outer side surface of the bottom portion of the bobbin. The ball is moved along the spiral guide grooves so as to perform the stopping operation and the releasing operation.
In the stopping operation, the ball is positioned at a stopping groove formed in the spiral guide groove so as to stop the rotation of the bobbin, thereby performing the stopping operation.
In the releasing operation, the ball positioned at the stopping groove is deviated from the stopping state to the releasing state by rotating the bobbin in an opposite direction. In this situation, the bobbin can be freely rotated in one direction.
However, in the conventional apparatus, since the ball is moved in only a radial direction along the guide groove but stopped in a circumferential direction, and the spiral guide groove formed in the bobbin is rotated, the ball cannot be easily moved. Therefore, there is a high likelihood that a malfunction can occur, so that the stopping and releasing operations cannot be precisely performed.
The present invention provides an apparatus for winding a cord, in which a ball is moved along a circular guide groove, thereby precisely performing stopping and releasing operations without the risk of malfunction.
The present invention provides an apparatus for winding a cord. The apparatus comprises: a winding case including a first plate in which one end of a fixing shaft is supported at a center portion, a second plate in which the other end of the fixing shaft is supported at a center portion and a first guide groove is formed in an inner surface, a first sidewall formed between one ends of the first and second plates and having a first through hole, and a second sidewall formed between the other ends of the first and second plates to be opposite to the first sidewall and having a second through hole; a cup-shaped bobbin of which a shaft hole is rotatably inserted onto the fixing shaft between the first and second plates and which has a second guide groove radially extended from the shaft hole on an outer surface of a bottom surface contacted with an inner surface of the second plate; a ball inserted into a space formed by the first and second guide grooves so as to be moved along the first guide groove according to a rotational direction of the bobbin; a spiral spring which is disposed at an inside portion of the bobbin and of which one end is fixed to the fixing shaft and the other end is mounted on a sidewall of the bobbin so as to provide rotational force to the bobbin in one direction; and a cord of which a middle portion is fixed to the bobbin, and extended portions extended from the middle portion toward which both sides are wound on an outer surface of the bobbin by the rotational force of the spiral spring, and in which one of the extended portions is extended through the first through hole of the first sidewall to an outside of the winding case, and the other is extended through the second through hole of the second sidewall to the outside of the winding case.